Apo-cal (CAN), Calciday, Calcite 500 (CAN), Calsan (CAN), Caltrate, Chooz, Equilet, Os-Cal, Oyst-Cal, Oystercal, Tums
Pregnancy Category C
Essential element of the body; helps maintain the functional integrity of the nervous and muscular systems; helps maintain cardiac function, blood coagulation; is an enzyme cofactor and affects the secretory activity of endocrine and exocrine glands; neutralizes or reduces gastric acidity (oral use).
- Dietary supplement when calcium intake is inadequate
- Treatment of calcium deficiency in tetany of the newborn, acute and chronic hypoparathyroidism, pseudohypoparathyroidism, postmenopausal and senile osteoporosis, rickets, osteomalacia
- Prevention of hypocalcemia during exchange transfusions
- Adjunctive therapy for insect bites or stings, such as black widow spider bites; sensitivity reactions, particularly when characterized by urticaria; depression due to overdosage of magnesium sulfate; acute symptoms of lead colic
- Combats the effects of hyperkalemia as measured by ECG, pending correction of increased potassium in the extracellular fluid (calcium chloride)
- Improves weak or ineffective myocardial contractions when epinephrine fails in cardiac resuscitation, particularly after open heart surgery
- Symptomatic relief of upset stomach associated with hyperacidity; hyperacidity associated with peptic ulcer, gastritis, peptic esophagitis, gastric hyperacidity, hiatal hernia (calcium carbonate)
- Prophylaxis of GI bleeding, stress ulcers, and aspiration pneumonia; possibly useful (calcium carbonate)
- Unlabeled use: treatment of hypertension in some patients with indices suggesting calcium "deficiency"
- Allergy to calcium; renal calculi; hypercalcemia; ventricular fibrillation during cardiac resuscitation and patients with the risk of existing digitalis toxicity.
Available Forms: Tablets--500, 650, 975 mg, 1 g, 1.25 g, 1.5 g; powder--1250 mg; injection--10%, 1.1 g/5 mL
Calcium carbonate or lactate
500 mg---2 g PO, bid---qid.
0.5---2 g PO calcium carbonate as needed.
For IV use only: 1 g contains 272 mg (13.6 mEq) calcium.
500 mg---1 g at intervals of 1---3 d.
500 mg promptly. Observe patient for signs of recovery before giving another dose.
Hyperkalemic ECG disturbances of cardiac function:
Adjust dose according to ECG response.
500 mg---1 g IV or 200---800 mg into the ventricular cavity.
IV infusion preferred: 1 g contains 90 mg (4.5 mEq) calcium. 0.5---2 g as required; daily dose 1---15 g.
IM or IV use: 1.1 g contains 90 mg (4.5 mEq) calcium; solution for injection contains 1.1 g/5 mL. 2---5 mL IM; 5---20 mL IV.
500 mg/kg per day IV given in divided doses.
Exchange transfusions in newborns: 0.5 mL after every 100 mL of blood exchanged.
Metabolism: Hepatic; T1/2: 1---3 h
Distribution: Crosses placenta; passes into breast milk
Excretion: Feces, urine
- Preparation: Warm solutions to body temperature; use a small needle inserted into a large vein to decrease irritation.
- Infusion: Infuse slowly, 0.5---2 mL/min. Stop infusion if patient complains of discomfort; resume when symptoms disappear. Repeated injections are often necessary.
- Incompatibilities: Avoid mixing calcium salts with carbonates, phosphates, sulfates, tartrates, amphotericin, cefamandole, cephalothin, cefazolin, clindamycin, dobutamine, prednisolone.
- CV: Slowed heart rate, tingling, "heat waves" (rapid IV administration); peripheral vasodilation, local burning, fall in blood pressure (calcium chloride injection)
- Metabolic: Hypercalcemia (anorexia, nausea, vomiting, constipation, abdominal pain, dry mouth, thirst, polyuria), rebound hyperacidity and milk-alkali syndrome (hypercalcemia, alkalosis, renal damage with calcium carbonate used as an antacid)
- Local: Local irritation, severe necrosis, sloughing and abscess formation (IM, SC use of calcium chloride)
Clinically important interactions
- Decreased serum levels of oral tetracyclines, salicylates, iron salts with oral calcium salts. Give these drugs at least 1 h apart.
- Increased serum levels of quinidine and possible toxicity with calcium salts
- Antagonism of effects of verapamil with calcium
- Decreased absorption of oral calcium when taken concurrently with oxalic acid (found in rhubarb and spinach), phytic acid (bran and whole cereals), phosphorus (milk and dairy products)
- Drug-lab test
- False-negative values for serum and urinary magnesium
History: Allergy to calcium; renal calculi; hypercalcemia; ventricular fibrillation during cardiac resuscitation; digitalis toxicity
Physical: Injection site; P, auscultation, BP, peripheral perfusion, ECG; abdominal exam, bowel sounds, mucous membranes; serum electrolytes, urinalysis
- Give drug hourly for first 2 wk when treating acute peptic ulcer. During healing stage, administer 1---3 h after meals and hs.
- Do not administer oral drugs within 1---2 h of antacid administration.
- Have patient chew antacid tablets thoroughly before swallowing; follow with a glass of water or milk.
- Give calcium carbonate antacid 1 and 3 h after meals and hs.
- Avoid extravasation of IV injection; it irritates the tissues and can cause necrosis and sloughing. Use a small needle in a large vein.
- Have patient remain recumbent for a short time after IV injection.
- Administer into ventricular cavity during cardiac resuscitation, not into myocardium.
- Warm calcium gluconate if crystallization has occurred.
- Monitor serum phosphorus levels periodically during long-term oral therapy.
- Monitor cardiac response closely during parenteral treatment with calcium.
Drug-specific teaching points
- Report any pain or discomfort at the injection site as soon as possible.
- Take drug between meals and at bedtime. Ulcer patients must take drug as prescribed. Chew tablets thoroughly before swallowing, and follow with a glass of water or milk.
- Do not take with other oral drugs. Absorption of those medications can be blocked; take other oral medications at least 1---2 h after calcium carbonate.
- The following side effects may occur: constipation (can be medicated), nausea, GI upset, loss of appetite (special dietary consultation may be necessary).
- Report loss of appetite; nausea, vomiting, abdominal pain, constipation; dry mouth, thirst, increased voiding.
Adverse effects in Italic are most common; those in Bold are life-threatening.